My DD's team practices and or plays on the weekends. They also do fielding, pitching and hitting at their facility during the week, but it is not required for players to attend. That being said it is recommended that the girls take lessons etc on their own, but it is not required. Their philosophy is if you play, hit or pitch well you will get plenty of playing time. If not then not so much.
So, it is up to the kids to do what is needed to compete. If they can go to the park with dad or mom and can get the job done that's fine. If they need lessons then that's the way they need to go, but either way it's their choice. It's very similar to school. If your parents can help with homework and such when needed that's great, but if you need a tutor to keep the grades up then that's what you do. The bottom line is if your kid wants to compete at a certain level you do what you can to give them the tools.